package com.qf.controller;

import com.qf.pojo.Cart;
import com.qf.pojo.User;
import com.qf.service.CartService;
import com.qf.service.serviceImpi.CartServiceImpl;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.List;

@WebServlet("/cart")
public class CartController extends BaseServlet {

    /**
     * 创建购物车
     * @return
     */
    public String create(HttpServletRequest request, HttpServletResponse response) {

        //1. 获取商品id
        String pid = request.getParameter("pid");

        //2. 获取session会话中当前用户的用户id
        User user = (User)request.getSession().getAttribute("loginUser");
        if (user == null) {
            //如果获取不到用户对象, 说明用户没有登录, 跳转到登录页面
            return "redirect:/login.jsp";
        }

        //3. 调用service业务层, 将购物车存入到数据库中
        CartService cartService = new CartServiceImpl();
        cartService.createCart(user.getId(), Integer.parseInt(pid));

        //4. 跳转到购物车查询列表方法
        return "redirect:/cart?method=show";
    }

    /**
     * 查询指定用户的购物车数据, 并跳转到购物车列表页面展示
     * @return
     */
    public String show(HttpServletRequest request, HttpServletResponse response) {
        //1. 获取session会话中当前用户的id
        User user = (User)request.getSession().getAttribute("loginUser");
        if (user == null) {
            //用户未登录, 从新登录
            return "redirect:/login.jsp";
        }

        //2. 根据用户id调用service查询这个用户的购物车数据
        CartService cartService = new CartServiceImpl();
        List<Cart> cartList = cartService.findCartListByUid(user.getId());

        //3. 将用户购物车的数据放入request域中, 带到页面中进行展示
        request.setAttribute("list", cartList);

        //4. 跳转到购物车列表页面展示
        return "forward:/cart.jsp";
    }

    /**
     * 修改购物车中购物项的购买数量
     * @param request
     * @param response
     * @return
     */
    public String update(HttpServletRequest request, HttpServletResponse response) {
        //1. 从会话中获取当前登录用户的id, 如果获取不到跳转到登录页面
        User user = (User) request.getSession().getAttribute("loginUser");
        if (user == null) {
            //用户未登录, 从新登录
            return "redirect:/login.jsp";
        }

        //2. 获取购物项主键id参数
        String cid = request.getParameter("cid");

        //获取购买数量
        String cnum = request.getParameter("cnum");

        //3. 调用service, 执行修改业务
        CartService cartService = new CartServiceImpl();
        cartService.updateCart(Integer.parseInt(cid), Integer.parseInt(cnum));

        //4. 跳转到购物车列表方法, 查看购物车中最新的数据展示
        return "redirect:/cart?method=show";
    }

    /**
     * 根据购物项主键id删除
     * @param request
     * @param response
     * @return
     */
    public String delete(HttpServletRequest request, HttpServletResponse response) {
        //1. 到session会话中获取当前登录用户对象, 获取不到说明没登录, 从新登录
        User user = (User) request.getSession().getAttribute("loginUser");
        if (user == null) {
            //用户未登录, 从新登录
            return "redirect:/login.jsp";
        }

        //2. 获取购物项主键id
        String cid = request.getParameter("cid");

        //3. 调用service根据购物项主键id删除
        CartService cartService = new CartServiceImpl();
        cartService.deleteById(Integer.parseInt(cid));

        //4. 跳转到购物车查询列表页面, 显示最新购物项数据
        return "redirect:/cart?method=show";
    }
}
